Ammonium cyanide


Ammonium cyanide
Ammonium cyanide
Identifiers
CAS number 12211-52-8
PubChem 159440
ChemSpider 140210 YesY
Jmol-3D images Image 1
Properties
Molecular formula NH4CN
Molar mass 44.0559 g/mol
Appearance colourless crystalline solid
Density 1.02 g/cm3
Boiling point

36 °C

Solubility in water very soluble
Solubility very soluble in alcohol
Related compounds
Other anions Ammonium hydroxide
Ammonium azide
Ammonium nitrate
Other cations Sodium cyanide
Potassium cyanide
Related compounds Ammonia
Hydrogen cyanide
 YesY cyanide (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Ammonium cyanide is an unstable inorganic compound with the formula NH4CN.

Contents

Uses

Ammonium cyanide is generally used in organic synthesis. Being unstable, it is not shipped or sold commercially.

Preparation

Ammonium cyanide is prepared in solution by bubbling hydrogen cyanide into aqueous ammonia at a low temperature

HCN + NH3(aq) → NH4CN(aq)

It may be prepared by the reaction of calcium cyanide and ammonium carbonate:

Ca(CN)2 + (NH4)2CO3 → 2 NH4CN + CaCO3


In dry state, ammonium cyanide is made by heating a mixture of potassium cyanide or potassium ferrocyanide with ammonium chloride and condensing the vapours into ammonium cyanide crystals:

KCN + NH4Cl → NH4CN + KCl

Reactions

Ammonium cyanide decomposes to ammonia and hydrogen cyanide; often forming a black polymer of hydrogen cyanide:

NH4CN → NH3 + HCN

It undergoes double decomposition reactions in solution with a number of metal salts. It reacts with glyoxal producting glycine (aminoacetic acid):

NH4CN + (CHO)2 → NH2CH2COOH + HCN

Reactions with ketones yield aminonitriles:

NH4CN + CH3COCH3 → NH2CH2CH2CH2CN + H2O

Toxicity

The solid or its solution is highly toxic. Ingestion can cause death. Exposure to the solid can be harmful as it decomposes to highly toxic hydrogen cyanide and ammonia.

Chemical Analysis

Elemental composition: H 9.15%, C 27.23%, N 63.55%.

Ammonium cyanide may be analyzed by heating the salt and trapping the decomposed products. hydrogen cyanide and ammonia in water at low temperatures. The aqueous solution is analyzed for cyanide ion by silver nitrate titrimetric method or an ionselective electrode method; and ammonia is measured by titration or electrode technique.

References

  1. A. F. Wells, Structural Inorganic Chemistry, 5th ed., Oxford University Press, Oxford, UK, 1984.

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